In recent years, a liquid crystal display is widely applied to a consumer electronic product, such as a mobile phone, a portable computer, a flat television and the like. The liquid crystal display includes a backlight module for providing a surface light source for a liquid crystal display panel. According to different positions of the light source, the backlight module may be divided into an edge-lit backlight module and a direct-lit backlight module, wherein the light source of the edge-lit backlight module is arranged on a lateral side of a light emergent surface, and the light source of the direct-lit backlight module is arranged on a backside of a light emergent surface.